Timing device



' J. OGDEN Oct. 22, 1946.

TIMING DEVICE Original Fiied Sept. 21, 1940 Patented Oct. 22, 1946 TIMING DEVICE Jack Ogden, Huntington Woods, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Original application September 21, 1940, Serial No. 357,794. Divided and this application September 22, 1945, Serial No. 617,991

' This invention relates to timing devices and more specifically to electrical circuits for measuring minute time intervals and is a division of S. N. 357,794 filed September 21, 1940, The need for means for measuring very small increments of time ha increased considerably and at the present time devices of this nature are much in demand. As one example which may be mentioned is that of timing the various steps of Welding machine cycles which are at the most a few electrical cycles long. There are of course many other instances in which time intervals approximately the length of electrical cycles must be measured for correct timing and operation.

It is therefore an object of my invention to provide timing means capable of measuring small time periods.

It is a further object of my invention to provide such a timing device as can be easily transported and connected to means whose actuation it is desired to time.

It is a still further object of my invention to provide timing means which is easily and accurately adjusted to read the required period.

With these and other objects in view which will become apparent as the specification proceeds, my invention will be best understood by reference to the following specification and claims and the illustration in the accompanying drawing, in which: 'Thelfigure shows a schematic Wiring diagram of the measuring system of my invention.

Referring now more specifically to the drawing, there is provided a power supply line I40 of for example the conventional 110 volt 60 cycle to supply power for the indicating apparatus. This incoming 110 volt line is connected to two rectifier tubes I42 and I44 which supply the necessary direct current from the usual alternating current supply. The tube I42 supplies direct current across a pair of condensers I46 and I48 and a resistor I50 through lines I52 and I54. The line I54 continues and is connected to a relay coil I56 the opposite side of which is connected by line I58 to a variable resistor I60, the adjustable tap I62 of which is connected by line I64 to line I66, this line being connected in turn to a stationary switch point I68, Between lines I54 and I66 there is provided a fixed condenser I10. The adjustable tap I12 engaging resistor I50 is connected by line I14 to a movable switch point I 16 actuated by a relay coil 58 and cooperates with the stationary switch point I68 just described. Thus the tube I42 supplies power to charge the condenser I18 and en- 7 Claims. (Cl. 16115) ergizes the relay coil I56. The tube I44 on the other hand supplies power across another pair of condensers I18 and I which are in parallel across a variable resistor I82 through lines I84 and I86. The resistor I82 has two adjustable taps l88 and I90, the first of these being connected through line I92 to a cathode I94 of a magic eye or 6E5 tube of the cathode ray type. Line I92 is also connected to one side of a resistor I96 and one side of condenser I98, the opposite side of the last-named resistor being connected by line 200 to a stationary contact 202. The opposite side of the last-named condenser is connected through line 204 to line 206, the latter being connected to a movable switch element 208 and also to the grid or control element 2I0 of the 6E5 tube. The stationary switch member cooperating with the movable switch element 208 is connected by line 2I2 to a movable switch member 2I4 on the member actuated by the relay coil 58. Line 204 continues and is connected to a movable switch point 2I6 movable with the members I16 and 2| 4 all three of which are supported on a common bracket and moved simultaneously by actuation of the relay coil 58. It should also be noted that the switches I68-l16 and 2I62I8 are closed upon energization of the relay coil 58 while switch 202-2I4 is opened upon such energization. Any suitable spring bias means (not shown) may be provided to return the movable switch arm upon deenergization of the coil '58 to its deenergized positionto close switch 202--2I4 and open switches I68--I16 and 2I62I8 The movable contact 2I6 cooperates, as mentioned, with a stationary contact 2I8 which is connected by line 220 with a resistor 222 the opposite side of which is connected by a line 224 to a variable resistance 226 which is in turn connected to the line I86. The remaining elements 228 and 230 of the 6E5 tube are connected across a resistor 232 and thence by common line 234 to the adjustable tap I on the resistor I82. The incoming lines 56 and 28 connected to the operating relay 58 are supplied with power from the mechanism whose operating periods it is desired to measure. They may be connected across certain portions of a welding circuit to determine how long the equipment is energized for any portion of its cycle or they may be connected with some other equipment whose operating cycle it is desired to time.

The over-all operation of the system may be briefly described in that when the relay coil 58 is energized the 6E5 pattern closes and if the time period is such that the pattern will just close without over-lapping the operator will be able to determine from the setting on the variable resistor 226 which is calibrated in timed periods how long that time interval is. If the 6E5 tube closes too far or over-laps then more resistance will be introduced into the circuit and the reading will therefore be less or vice versa, if the tube does not entirely close then less resistance is inserted so that the sam may entirely and completely be closed. Therefore, when relay 58 is energized and attracts its armature switches I58--I16 and 2I8-2I6 close and switches 202- 2I4 open the closure of switches I68-I1B causes the energization of relay coil I56 through the following circuit: From the output of tube I42, line I54, relay coil I56, line I58, resistor I60, tap I62, line I64, line I66, switch contact I68, switch contact I16, line I14, adjustabl tap I12, resistance I50 to line I52. At the same time tube I42 supplies voltage to the condenser I through an obvious circuit. When the relay coil I56 is then energized it attracts its armature and opens the switch 203. With the opening of this switch and also switch 202--2 I4 the short circuit which has been applied to condenser I98 is removed and the closure of switch 2I6-2I8 applies to this condenser through a circuit to be described the output of the tube I44. This circuit is as follows: line I86, variable resistor 226, line 224, resistor 222, line 228, switch 2I6-2I8 directly to condenser I 98. The amount of energy applied to the condenser I98 is regulated by the setting of the variable resistor 226, the dial of which is calibrated in cycles. This voltage is applied to the control element or grid ZIO of the 6E5 tube and causes the shadow portion to become smaller and if resistor 226 is properly set will disappear entirely, the setting of this dial indicating the length of time of the operation. The necessary operating voltages for the remaining elements of the tube are provided by lines I92 and 234 through resistance I82 by obvious circuits.

When the machine cycle has been completed and the relay 58 deenergized, the switches I68- I16 and 2I6--2I8 will open and switch 202--2I4 will'reclose, the opening of switch 2l6-2IB will remove the supply of energy from the condenser I98 and the opening of the switch I68-I16 will open the circuit to the relay coil I56. However, this relay will not immediately drop its contact 208 inasmuch as the condenser I10 is directly across the relay terminals. This charge will slowly leak off and in a short time the switch 208 will drop, completing the short-circuit around the condenser I98 and discharging the same, returning the apparatus to its initial condition. This delay is provided to allow a time to elapse between the charge and discharge of the condenser I98 so that the retina of the eye of the operator or observer may follow the fluctuations on the shadow in the cathode ray tube. It will thus be evident that as the variable resistor 226 is altered to cause the shadow to completely disappear without over-lap that the reading on this dial will give the duration of the portion of the cycle being measured.

In most equipment passing through or operating on a complete working cycle there is a successive reoccurrence of that portion of that cycle in which the operator may be interested which will cause the indications on the 6E5 tube to re-appear at rapid intervals and the relay 58 would therefore be rapidly and successively energized for a series of similarily timed impulses for the given timed interval to be measured. Since however, a series of impulses is being studied it will be comparatively easy for the operator to adjust the resistor 226 for, as far as he will be concerned, the cathode ray tube appears to have the opening or closing relatively stationary and he can adjust to the proper point. If it is desired to study a different portion of the working cycle it will only be necessary to so connect lines 56 and 28 so that they will be energized by the new portion of the complete cycle whose duration it is now desired to measure.

I claim:

1. In a timing device, a cathode ray tube having a target and control electrode, a condenser connected to said control electrode whereby the charge thereon will alter the pattern on the target, a source of voltage connected to the condenser, a. variable resistance connected between the source and the condenser, switching means to control .the circuit whereby the condenser is periodically charged and discharged and the pattern on the target is simultaneously varied as the switching means is operated, and automatically operated delay means connected into said circuit to prevent immediate discharge of the condenser upon deenergization of the switching means.

2. In a timing device, a cathode ray tube having a target, a source of power, a variable resistance connected thereto and having a calibrated dial, a control electrode in the tube, a condenser connected thereto and to the resistance, whereby the charge on the condenser controls the electrode potential and the pattern on the target and the resistance varies the rate of charge so that a desired pattern may be obtained, the dial acting as an index means, a shunt circuit for shorting out the condenser to discharge the same, switching means in the shunt, relay means to control the switching means and delay means to prevent the immediate deenergization of the relay and shorting of the condenser upon general deenergization of the system.

3. In a timing device, a cathode ray tube having a target and control electrode, a condenser connected to said control electrode whereby the 'charge thereon will alter the pattern on the target to indicate a predetermined charge, a source of voltage connected to the condenser, a variable resistance connected between the source and the condenser, switching means operating in successive timed sets of series, said sets having dinerent length pulses but all of one series being of the same length to control the circuit whereby the condenser is brought to said predetermined charge as indicated by the cathode ray tube by a single series of pulses and if the length of the pulses of a series is changed the resistance may be varied to still bring the condenser to the same charge, and an indicating dial on said variable resistance to denote the time during which the series of pulses was applied.

4. In a timing device, a cathode ray tube having a target, a control electrode in said tube whose potential controls the configuration on said target, a source of power, variable resistance means connected to the source, a condenser connected to said variable resistance and to the control electrode, and a periodically timed switch controlling the circuit whereby as the length of time the switch is closed is varied, the rate of charging the condenser may also be varied to bring the condenser up to a predetermined charge as indicated by the configuration on the cathode target.

5. In a timing device, a cathode ray tube having a target thereon capable of producing a predetermined configuration, a control electrode for said tube whereby when a certain voltage is applied to the electrode the configuration will be produced, a condenser connected to the electrode, the voltage thereacross being applied to the electrode, a source of power of substantially constant voltage, a variable resistance and a switch connected in series between the source and the condenser, means operating said switch periodically for similar time periods whereby by regulating said resistance the charge on said condenser may be brought to a given Value though the time period may be changed by altering the voltage applied and therefore the desired configuration will be obtained to indicate this value.

6. In a timing device, a cathode ray tube having a target thereon capable of producing a predetermined configuration, a control electrode for said tube whereby when a certain voltage is applied to the electrode the configuration will be produced, a condenser connected to the electrode, the voltage thereacross being applied to the electrode, a source of power of substantially constant voltage, a variable resistance and a switch connected in series between the source and the condenser, means operating said switch periodically for similar time periods whereby by regulating said resistance the charge on said condenser may be brought to a given value though the time period may be changed by altering the voltage applied and therefore the desired configuration will be obtained to indicate this value, and dial means in conjunction with said resistance to indicate the time period involved since that is proportional to the voltage applied.

7. In a timing device, a cathode ray tube having a target and control electrode, a condenser connected to said control electrode whereby the charge thereon will alter the pattern on the target to indicate a predetermined charge, a source of voltage connected to the condenser, a variable resistance connected between the source and the condenser, switching means operating in successive time sets of series, said sets having dilferent length pulses but all of one series being of the same length to control the circuit whereby the condenser is brought to said predetermined charge as indicated by the cathode ray tube by a single series of pulses and if the length of the pulses of a series is changed the resistance may be varied to still bring the condenser to the same charge.

JACK OGDEN. 

